AES E-Library

AES E-Library

The RCA Quadulator

Cutting of master lacquers for discrete quadraphonic (CD-4) records requires a device for obtaining sum and difference signals, a method of angular modulation of the 30 kHz carrier and associated signal processors. A new modulation system using phase-lock loop circuitry will be described which results in wider dynamic range and lower distortion than previous techniques, and is of far simpler construction. Careful examination of the subjective effect of individual signal processors has led to a further reduction in size and complexity.